I have had mixed results with bi-pods. Getting them "loaded" to get the springiness out of them is pretty important. If you want to shoot for groups, you probably want bags alone.

I shoot a lot of .22 and the single best thing I have found in improving accuracy is the ammo. Good ammo, SK,RWS,Lapua std, Rifle Match, Norma TAC, Wolf, Center X and some others are just head and shoulders above anything I have seen from American manufacturers. What they have in common is a sub-sonic bullet of about 38-40 gr. and some sort of heavy greasy lube. The domestic ammo that I shoot is all reserved for pistol or plinking with a Marlin 39a, Winchester 9422 or a 10-22 or pistols. I do have three bolt guns that have been worked on for bedding and triggers. A Ruger 77-22, CZ 452 Trainer and an Anschutz MPR64 and they will all shoot dime size 5 shot groups at 50 yards and the Ruger and the Annie have shot the same size group at 100 yards ( not often though ). The wind really causes problems at that distance.

If the rest of your rig is rock solid, good groups are pretty easy to shoot. Most .22 matches are shot at 25 and 50 yards and my test targets from Anschutz were shot at 50 meters. I can duplicate that target with all three rifles. I HAVE done it at 100 yards but it is VERY difficult. As I said, to much other stuff going on.